Pacemaker Install

[Slidin Gator]

With the water dropping, froggin's been good, but the engine's been acting up and a mag drop test confirmed I needed some ignition work. My first thought was to start troubleshooting the mags, but I quickly decided to move on to the correct plan.

A few years back, I realized that VHF dog tracking gear and airboat mag ignition don't play well :banghead: :banghead: Magneto Ignition is inherently "Noisy" in the radio frequency spectrum and I found that it severely limited my ability to track dogs while running. So I did my first conversion to a Pacemaker electronic ignition and dam'n if I could'nt track dogs :cheers:

So instead of F))ckn around with mags again, I called Darrin at Pacemaker. Since he had nothing else to do, he boxed up a new ignition system and shipped it right off to me. :cheers:

Well, just to go full nerd, I pulled out my Okeechobee Oscilloscope to document all this. Back in the day, when the TV screwed up like this, I'd go out in the driveway and fire up my CB, cause a flickering TV said party in the woods to me. :drunken:

Here's the Magneto version.

The next O Scope run is with the new Pacmaker ignition, no other changes (except camera mount...).

The engine is presently running non-resistor plugs, switching to resistor plugs will clean up the rest of the noise.


Oh yah, engine fires much quicker now :thumbleft:

 

[Gary S]

You don't get Gunsmoke?

 

[Slidin Gator]

My wife plays Gunsmoke in a continuous loop, interrupted by cooking shows. Just when I was feeling pretty good about the random movie that was playing on the old TV :banghead: :banghead:

For the full nerd out, I dug out my $20 Software Defined Radio (SDR) dongle that I bought a few years ago to hack the tracking collars.

The Garmin collars transmit on VHF frequencies just below the marine band. They use the MURS frequencies (multi use radio service) and transmit at 2 watts. The Astro system broadcasts location for 1/2 second every 5 seconds, which is why there is a 10 dog limit. The Alpha system uses the same 5 frequencies but broadcasts for 1/8 second every 2-1/2 seconds to achieve 20 dog tracking capability.

In the case below the collar is about 100 feet from the receiver. Move it 1/2 mile away and the RF noise from the mags walks all over the collar Transmission.

 

[Slidin Gator]

Backing up to the beginning, all of the new FWC brochures for WMA's which allow some form of dog hunting include the following (new) language:

Effective July 1, 2021, the taking or pursuing of deer, wild hog, fox, or coyote with dogs is prohibited unless each dog is
equipped and monitored with devices that allow remote tracking. Remote behavior correction devices will be required beginning
July 1, 2022.

I understand why FWC is adding these requirements (to cut down on user conflicts and dogs entering private land) and have been using these tools for a while. They really do improve efficiency so we can spend more time hunting, less time hunting dogs. But, given the likelihood that there will be more users on the crowded MURS frequencies, this install helps maximize performance of my gear.

On to the actual installation, here is what shows up in the box for a 6 cylinder Lycoming:

- Coil pack (6 coils total) with mounting brackets
- Fly wheel timing pickup
- Wiring Harness
- User interface panel with mounting bracket
- Full set of high quality, pre-labeled, Silicone spark plug wires
- Accessory case mag blanking covers (to blank off case once mags are removed)
- Nylon tubing to provide vacuum signal for MAP sensor
- Box of miscellaneous bits.

The only items not included are a crimping tool for the DIN style terminations on the wiring harness, a 5/16-18 tap and a handful of 1/4-20 fasteners. If you want, Daren will pre-terminate the wiring harness and you will end up with some extra length. As I already had a set of crimpers, I choose to terminate things myself after mounting the interface panel under the rear rider foot panel. Do note that after installation there is no need to access the interface panel, but it does provide a readout of actual timing and engine RPM, so it can be mounted in place of a Tach, it's going to be very accurate on RPM, otherwise the engine is not gonna run.

All of the wiring utilizes gasket sealed DIN connectors and the user interface display is sealed.

 

[Slidin Gator]

The coil packs mount to the top of the engine case, using the stern 3 case split bolts. Note that the paint is removed from the mounting surfaces of the plates as the coils are grounded to the case at this point. I took a wire wheel to the case to clean it to bare metal in the mating areas and then coated everything with never seize to maintain a good connection. Also note a waterproof fuse holder in between the coils that holds a standard automotive 20 amp blade fuse.

Note that each coil features two spark plug wire connections, each marked with the appropriate cylinder. Also note that each coil drives one plug on each of two cylinders. Each pair of cylinders reaches TDC at the same time, but the power stroke alternates, so the plugs actually fire on the exhaust stroke as well as the power stroke. The STBD side coil pack drives the bottom plugs, the Port side coil pack drives the top plugs, so the system provides redundant ignition coils and will continue to fire each cylinder in the event of failure of a single coil or complete coil bank, just like dual mags.

I will also note that the system will operate at a fixed timing setting (22 degrees per Pacemaker's website) if the user interface panel (MAP sensor interface) fails or is completely disconnected. The connectors at the stern end of each coil (bottom of the picture) provide power and timing signal to each bank of coils. You can also perform a test similar to a Mag drop test by manually disconnecting one coil pack at a time and running on a single set of plugs. But given that this requires reaching into the cage, it requires shut down for each step in the test.

 

[Slidin Gator]

The next step is mounting the timing pickup. Since the pickup is mounted close to the alternator belt, on my original installation I was concerned about a belt failure trashing the pickup. Since then I have failed a belt and never even knew it (until noting the voltmeter stuck on 12 volts). Regardless, the actual pickup is a standard GM component and I bought a spare for $15 to carry in my kit.

 

[Slidin Gator]

Next I installed the MAP sensor connection. This install is on an injected 540 so the MAP signal comes from the intake manifold. There are 1/8" plugs on the PORT side, bottom of the intake manifold. Per Daren I used the plug shown, the kit comes with the proper fitting. Daren advises that the system will not work if you use one of the ports on the cylinder intake (which is a common point for manifold vacuum gauges on aviation applications), I assume the signal is too noisy. Carbureted engines require drilling and tapping a port in a specific location on the engine side of the carb throttle.

Using the nylon tubing included in the kit, route from this fitting to a rubber hose dangling from the user interface panel (pretty obvious). Note that I do carry a spare 1/8" pipe plug to plug off this port in case the tubing is damaged on the water. The engine will run fine without the MAP connection, but the system will run at fixed timing.

 

[Slidin Gator]

All of the above can be completed without changing anything on actual operation of the engine. I actually installed all of the above one day and went out frogging that night, still running on mags. But, since my Port mag was missing on a cylinder (one of the reasons I decided to pull the trigger on a Pacemaker) I could not wait to get the new ignition up and running.

So, the next step is to add the timing targets to the flywheel. Start by rotating the engine to the TDC mark on the flywheel. Since I knew my flywheel was timed properly, I did not bother confirming that cylinder #1 was actually at TDC. But, it is good practice to pull a plug from #1 and confirm the piston is at TDC as it is possible to install the flywheel at the wrong orientation. With mags, this does not create an issue unless timing mags, with the Pacemaker, the flywheel does have to be installed at the correct rotation. It does not matter if #1 is on the power or exhaust stroke, just rotated to TDC.

The kit comes with 7x 5/16-18 by 3/4" long, flat face, steel set screws. While it may be tempting to use SST set screws, realize these are magnetic targets for the timing pickup, so they need to be magnetic steel as supplied.

The flywheel as standard features 12x 1/4" diameter holes at 30 degrees apart, normally used for adding balance weights. The Pacemaker uses 6 of these holes for timing signals plus a 7th, new hole used to identify the #1 cylinder on each rotation and is located at 10 degrees after #1 TDC. The installation kit comes with a drill guide to make it easy to add this new hole. The picture below shows the flywheel from the belt side (engine side) of the flywheel with the #1 TDC mark (note the 25 deg BTDC mag timing mark to the right side of the picture).

Use 2x 1/4" bolts to attach the drill guide to the flywheel using the two holes shown (#1 TDC hole and and the next hole at 30 deg. after #1 TDC). Note that the guide features 2 more holes, one is 1/4" diameter for drilling and the other is 5/16 for use as a tap guide. Arrange the guide with the 1/4" drill guide closest to the #1 TDC hole. This puts the new hole at 10 deg. after TDC.

Drill through this guide and the flywheel with a 1/4" drill bit.

Next, tap the holes using a 5/16-18 tap. Note that the standard call out for tap drill is 17/64 (0.265"), but it is standard practice to use a slightly smaller bit size when tapping aluminum. Either way, I used a 1/4" drill and good old Aluminum Tap Magic and everything works like butter. The result should match the following. Note in particular which holes are tapped and which are left untouched.

 

[Slidin Gator]

Getting towards the end. Re-install the flywheel. Assuming the engine has not been rotated since removal, the TDC mark should install at the top. Install the prop hub and prop, torqueing all to specification (per the prop and hub supplier).

Using blue loctite, allen wrench and a set of 0.040" feeler gauges, coat each screw with Loctite and run them into the threaded holes. Set each screw at 0.040" gap from the timing pickup.

 

[Slidin Gator]

With the above complete it is time to add power. The wiring harness has a single red wire sticking out, beyond the interface panel connector. Route this wire to a switched 12 volt supply that will be used to turn the ignition on and off. If replacing mags, this would involve re-wiring one of the mag switches to supply +12 VDC. This leaves a new, unused switch. I like to use this switch as a starter cut out, wiring 12 volts through the switch, to the starter button and on to the starter. When starting, turn the switch on and hit the starter button. Once started, turn the switch back off. This provides additional safety against accidently engaging the starter, when the engine is on or off. That's just me, use it for what you want.

Now the system can be energized, but DO NOT START THE ENGINE YET. As delivered the unit is not configured for operation and needs to be adjusted. With the power switch on, the interface panel should light up and display a bunch of random numbers. Unscrew the 4 Philips head screws on the cover panel to access the adjustment pots.

The baseline settings provided with the instructions are 220 2200 250 10. These settings do work fine for most applications. The decode on these settings is as follows:

220 = 22.0 degrees base timing (22 Deg BTDC). This is the timing that the unit would set at idle without any MAP setting (i.e., if you don't hook up the black vacuum line).

2200 = 2200 RPM, this is the RPM that final timing comes in, regardless of MAP signal.

250 = 25.0 degrees final timing. At all RPM's above the 2200 final timing setting above, the unit will operate at 25 Deg BTDC.

100 = 10.0 degrees of MAP range.

Starting with no MAP signal (vacuum line not connected) the timing is interpolated from 22 degrees at idle to 25 degrees at 2200 RPM. Basically, as RPM increases, timing advances slightly. This is analogous to the timing weight and spring system in an old school Chevrolet HEI distributor system. As engine RPM increases, engines need a bit more advance to optimize the peak power point in the stroke. Realize that the piston is moving faster, so there is less time for combustion to occur, therefore it needs to be initiated sooner.

The 10 degrees of MAP (final setting of 100 above) provides additional timing at part throttle above the base timing slope. At idle the throttle is closed and the engine is at maximum vacuum, in which case the Pacemaker adds full map for an idle timing of 22 + 10 = 32 Deg BTDC. This is one of the huge advantages of the Pacemaker vs. fixed mag timing and is the equivalent of the vacuum advance system on the old school HEI systems. Because the throttle is closed, the fuel/air mixture introduced to the cylinder is low, there is less fuel and air to combust. The speed of combustion is slower, so throwing the spark sooner gives more time for the combustion to occur at the optimum point for maximum power from the available fuel. This means the engine needs less fuel and idles smoother.

Now, press the throttle partially, intake manifold vacuum drops, leading to a lower MAP signal. The Pacemaker reduces timing to somewhere between the full map (32 degree ) and base timing (22 degree) points. At cruise (say 1800 RPM), timing will be somewhere in the middle (let's just say 29 degrees...). This is a bit more than the fixed 25 degree mag setting and again helps improve economy and part throttle response.

Now, mash the gas, manifold vacuum drops to minimum (closer to atmospheric pressure). The Pacemaker eliminates all of the Map timing and runs on the base timing curve between 22-25 deg BTDC as dictated by RPM alone.

The following is a chart I put together for settings on another setup. In this case we brought in final timing at 2,000 RPM vs. the 2,200 figure above. This is all a part of tuning that specific setup. Google "Ignition Timing" and you will find loads of theory covering the concepts of variable ignition timing.

Also note that there is an additional wire in the harness labeled "Nitrous". This is used if the engine runs Nitrous and would be tied into the same switch or signal used to activate the Nitrous system. When activated, the "Nitrous" mode decreases timing (using further adjustments), as timing advance needs to be decreased when pouring Nitrous into an engine. The Pacemaker actually has the ability to run 2 stages of nitrous timing settings for 2 stage nitrous systems, but that would be a special order system. Finally, there is also an external tach output that can used to drive a digital tach.

Once the pots are dialed in to the desired settings, button up the cover on the panel and fire that mother up :thumbleft:

 

[Gary S]

Pacemaker adds full map for an idle timing of 22 + 10 = 32 Deg BTDC.

I just put a new 2 blade whirlwind prop on a lycoming 180 and the instructions said not to exceed 26 degrees. I think that is what it said. I know it wasn't 32. Any idea why?

 

[Slidin Gator]

The instructions say not to exceed 25 degrees, Sensenich instructions are the same.

The concern is timing at full throttle. They are looking to limit maximum torque and vibration to the prop, as well as rule out racing applications.

With mags, timing is fixed, so set to 25. This is fine for a plane, they only idle to warm up but run constant at 2200 and up. Variable timing does not provide any real advantage.

With the Pacemaker settings described above the timing would limit out at 25 degrees at full throttle as well. Actually, from idle, if you mash the gas, timing would start at 22 deg and climb to 25 at 2200 RPM, staying at 25 to max RPM.

Timing only exceeds 25 under part throttle and idle conditions. In those conditions, torque is much less than maximum and the additional advance actually makes for a smoother running engine, which is better for the prop while using less fuel, particularly when frogging.

In summary, those instructions where written without consideration of variable timing systems.

 

[nunook]

I have attempted to reach out to Pacemaker several times on there "Contact" link but have not heard back anyone have good contact information? Looking for pricing for a gso-480

 

[kwanjangnihm]

These numbers were from a few years ago in a pacemaker thread.

Rodney 407-709-1278
Darrin 407-709-9578

 

[nunook]

Thanks

 

[smokster]

this is a great post. i just used it to install it on my sv 540 and it was easy to follow. thanks for the write-up

 

[Slidin Gator]

this is a great post. i just used it to install it on my sv 540 and it was easy to follow. thanks for the write-up

Thanks Smokster.

I see the pictures got deleted. I found them in a folder on my computer so I re-edited to put them back in.

Also, I carry a spare timing pickup and harness pigtail. It sits so close to the belt, but I have never had a problem with it. Regardless, the sensor is cheap enough and available on Amazon etc.